A family of related peptides has been discovered that works in concert to achieve salt and water homeostasis in the body. These peptides, termed natriuretic peptides for their role in moderating natriuresis and diuresis, have varying amino acid sequences and originate from different tissues within the body. This family of natriuretic peptides consists of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), Dendroaspis natriuretic peptide (DNP), and urodilatin (URO, or ularitide). Their tissue-specific distribution is as follows: heart (ANP, BNP, and DNP); brain (ANP, BNP, and CNP); endothelial cells (CNP); plasma (DNP); and kidney (URO). These peptides are constituents of a hormonal system that plays a critical role in maintaining an intricate balance of blood volume/pressure in the human body. For instance, urodilatin, a close analog of ANP secreted by kidney tubular cells, promotes excretion of sodium and water by acting directly on kidney cells in the collecting duct to inhibit sodium and water reabsorption. Like other natriuretic peptides, such as ANP and BNP, urodilatin has been studied for use in treating various conditions, including renal failure or congestive heart failure (see, e.g., U.S. Pat. Nos. 5,571,789 and 6,831,064; Kentsch et al., Eur. J. Clin. Invest. 1992, 22(10):662-669; Kentsch et al., Eur. J. Clin. Invest. 1995, 25(4):281-283; Elsner et al., Am. Heart J. 1995, 129(4):766-773; and Forssmann et al., Clinical Pharmacology and Therapeutics 1998, 64(3):322-330).
Cardiovascular diseases are the leading causes of death in the United Sates, regardless of gender or ethnicity. Among these diseases, congestive heart failure (CHF) is highly prevalent. According to the American Heart Association, the number of hospital discharges and the number of deaths due to CHF both rose roughly 2.5-fold from 1979 to 1999. Currently, about 5 million Americans have been diagnosed with CHF, and about 550,000 new cases occur annually (American Heart Association 2001). This life-threatening condition is accompanied by great financial impact. Thus, there exists a need for providing new and more effective methods for treating heart failure.
Previous studies have shown that the administration of ularitide is effective in treating heart failure patients. The present inventors have discovered a new method for ularitide administration that is surprisingly effective for treating heart failure of varying causes, particularly acute decompensated heart failure. The method of this invention can also be used for treating heart conditions that generally relate to abnormal fluid accumulation in the heart, e.g., myocardial edema.